To be frank, that line didn't just explode out of nowhere. That was a leak that had developed over time and got worse and worse. You should have been checking your oil level periodically and you would have seen the drop and would have taken it into the dealer and at least avoided the cost of the tow.
I just had my oil changed at the dealership I purchased it from a few months ago (November I believe), which included a full multi-point inspection. I had no reason to check the oil when I did not see or smell any sort of problem and had a recent inspection at a Chevy dealer. Again, I only knew there was a problem when I started smelling oil burning through the vent, which only began Sunday night. I sit in traffic a few days a week, and with the temperatures in Chicago I always have the vent going. I would have noticed if there was leaking to the point it was pouring on the cat like ended up happening that night, or any other spot of the compartment that was hot. There was no other warning sign before that point, so no reason to check the oil.
So either the previous dealer missed it, they saw it and did not inform me, or the leak only started after that change.
Regardless, even if I had for some reason seen it earlier I still would have called roadside to have it towed under warranty, per guidance by the dealership (who stated not to drive it).
The tow is the tow, I am not upset that about the cost of that ... it's the labor and part and the fact it was denied under warranty. The fact that they did not cover it, even though the service manager said it was the seals in the pipe, and then replaced it with a re engineered part shows that they are aware it's a problem.